The ultimate smart girl math is to go to trusted sources to understand what something will actually cost. We use calculators ...

You pay for a latte with money from your Starbucks app, so your bank account balance doesn’t change. That means the coffee was basically free, right? This is just one example of “girl math,” a trend ...

While I am financially savvy, I’m also into some lighthearted spending logic. And if your math brain works anything like mine, we might agree on some things: anything less than $5 is free; it’s smart ...